Problem $18-18($Algo$)$ A particular forecasting model was used to forecast a six month period. Here are the forecast and actual demands that resulted

April$-$ forecast $260$: actual $210$

May $-$ forecast $336$: actual $248$

June $-$ forecast $412$: actual $335$

July $-$ forecast $361$: actual $310$

August forecast $386$: actual $330$

Sept forecast $460$: actual $406$

$($A$)$ Find the tracking signal for each month

$($B$)$ Does the model used here five acceptable answers?